Light-Induced Excited Spin-State

In the same line, [Fe(qsal)2][Ni(dmit)2].2CH3CN has also been proven to show a cooperative spin transition based on n-n interactions between ligands [105]. Moreover, this compound is also one of the rare Fenl complex to exhibit the light-induced excited spin state trapping (LIESST) effect. 

LIESST Light induced excited spin state trapping... 

Decurtins, Giitlich, Hauser and Spiering (1987) Light-induced excited spin state trapping [219]. 

In 1984, Decurtins et al. discovered that the compound [Fe(ptz)6](BF4)2 (ptz=l-propyltetrazole) can be converted from the stable LS state to the metastable HS state by irradiation with green light at sufficiently low temperatures [14]. This phenomenon has become known as light-induced excited spin state trapping (LIESST) and is dealt with in detail by A. Hauser in a separate chapter in this series. Later, Hauser reported the reverse-LIESST effect, whereby red light is used to convert the compound back into the LS state [15]. 

Light-induced excited spin state trapping Light-induced thermal hysteresis 4- (p-Methoxyphenyl)-1,2,4-triazole 4- (p-Tolyl) -1,2,4-triazole Pyridine... 

LIESST Light Induced Excited Spin State Trapping... 

Photoinduced spin-related phenomena are a particularly important field of the solid-state photophysics, because fast spin switching is a prospective basis for applications in the field of spintronics. An illustrative example is the production of the metastable state of the iron propyltetrazole (ptz) complex [Fe(ptz)6](BF4)2 by laser light-induced excited spin-state trapping (LIESST) and the determination of the resulting structure by steady-state X-ray photodiffraction [68]. In another example, steady-state X-ray photodiffraction at cryogenic temperatures was successfully utilized to study photoinduced phase transition due to spin crossover in the tris(a-picolylamine)iron(II) complex [69]. The phase transition is accompanied by... 

Both photoinduced LS —> HS and HS > LS transitions involve transition through a 3Ti state, from which the system can relax into the LS and HS ground states via intersystem crossing processes. This reversible state switching has been summarized as light-induced excited spin state trapping (LIESST) effect,29 and especially for Fe-based compounds it can be conveniently traced by Mossbauer spectroscopy. 

Optical excitation of the LS( Aig) ground state at very low temperature in some thermally driven spin-crossover compounds may result in the formation of a trapped HS( T2g) metastable state. This effect, termed light-induced excited spin-state trapping (LIESST), has been discovered and described by Giitlich and co-workers... 

Spin crossover (SC) was observed for the first time by Cambi and Cagnasso [1]. This phenomenon was reviewed in a number of excellent reviews [2-7]. Because of its possible technological utilisation [8,9], spin crossover is widely studied at present. The usual induction of spin crossover is based on temperature variation but pressure and concentration variations may lead to the same effect. Recently, optical induction has been involved and such experiments were termed the LIESST (Light Induced Excited Spin State Trapping) and the reverse LIESST effects [7]. 

LIGHT-INDUCED EXCITED SPIN STATE TRAPPING (LIESST) 427... 

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